The Tokina 11-16mm F/2.8 AT-X 116 PRO DX-II is an update to the widely popular and award winning AT-X 116 PRO DX, 11-16 F/2.8 lens. This compact ultra wide-angle zoom has a bright constant F/2.8 aperture make viewing and auto focus possible in lower light situations but still maintaining a reasonable size and weight. Two Super-Low Dispersion glass elements and two aspheric glass allow the proprietary optical design to achieve excellent contrast and sharpness as well as controlling chromatic aberration. Tokina's exclusive One-touch Focus Clutch Mechanism allows the photographer to switch between AF and MF simply by snapping the focus ring forward for AF and back toward the lens mount for manual focusing. The lens is also designed to stand up to the rigors of daily use by photographers in a wide variety of capturing conditions and environments. Tokin has upgraded the coatings to this lens for improved optical performance.